Two overlapping disks have already been used in the screw type valves for the controlling or intercepting of fluid flow, said disks having openings or slots positionable either far from or in partial or total correspondence of each other.
One of the two disks is fixed whilst the other is controlled and movable in rotation on the fixed one so as to position the slots or openings of one far from or in partial or total correspondence of the other. According well known executions, the slots or openings of each disk occupy a section or panel of a surface and are also closed at the perimeter. The usual configuration of the fixed and movable overlapping disks still creates problems for the correct delivery of the fluid without having pressure loss and without limiting the theorectic flow.